Bayer’s Mirena enters Phase III study for NAEH

German pharma major Bayer (BAYN: DE) has announced the start of its Phase III study SUNFLOWER, an investigational study evaluating the efficacy and safety of 52mg levonorgestrel-releasing intrauterine system Mirena for the treatment of nonatypical endometrial hyperplasia (NAEH) in women.

NAEH is an abnormal thickening of the lining of the uterus, known as the endometrium, due to an imbalance between estrogen and progesterone levels. This condition is classified as nonatypical as the cells in the endometrium do not show signs of cancer. It can be asymptomatic, present with heavy or abnormal bleeding, or bleeding after menopause. If untreated, this condition may lead to uterine cancer. Approximately 121 out of every 100,000 women develop NAEH each year. Currently, there are no approved medical treatment options for this condition, presenting a high unmet medical need, noted Bayer, whose shares closed up more than 12% at 34.15 euros yesterday following the announcement.

Mirena/Kyleena/Jaydess (levonorgestrel) generated sales of 367 million euros ($426 million) in the third quarter of this year, up 16%.